I used to have a saying when I was younger

Only two types of people become cops: people who got thrown into a dumpster every day when they were kids and those who did the throwing.

I've moderated my stance a bit, largely because I have a couple of good friends who are cops and appear to be normal, well-adjusted people (though I've never seen them "on the job"). Not to mention folks here like mkovac (one of my very few highlighted posters) and the NYC cop whose handle I forget. But I agree with you that it is still a quite significant subset of cops who are either natural or created "hard guys". That it has come out that Chauvin was also a bouncer, the archetype of the "little people, little power, big problem" (I like that phrase and I'm stealing it) mentality, is another damning indicator. I think I'd be more surprised if it were shown that Chauvin didn't routinely act like this with virtually every perp, regardless of race. Note I'm not saying he's not racist or that racism didn't color his actions here - like you, I have no way to know.

My point is that we do society a disservice if we treat this as solely a racial issue. Blacks are unquestionably discriminated against from the word go in the criminal justice system and that issue has to be fixed first. But even if we succeed in eliminating all differences in how people of different races are treated by cops, we'd still have plenty of issues because so many cops are meatheads.

My layman's view is that the problem is one of leadership. My experience is that the "hard guy" mentality appears to cluster within individual police departments (e.g. SBPD). In my current hometown, every cop I have ever interacted with has been respectful, non-aggressive, and seemingly well-adjusted. I've lived in other places where seemingly every cop was an absolute dick. I'm sure there are socio-economic dynamics that explain some of those differences but I've lived in comparatively affluent areas where the cops were all assholes, too. I think this leadership issue starts at the top, because the national police organizations (e.g. the unions) perpetually equivocate (at best) or defend (at worst) their fellow cops in instances of alleged police brutality. The quickest path to improvement, in my opinion, is for these national organizations and nationally prominent police leaders to resist the instinct to circle the wagons every time there is an issue like this one. Accountability starts at the top.